Precast firebox



- Nov. 25, 1941.

E. c. LEWIS PRECAST FIREBOX Filed 0015. 31, 1940 ELWOOD C. LEWIS BY 0% ATTOR EY I g INVENTOR Patented Nov. 25, 1941 UN-l-TE' D STATES PAT 263,926; PRECAST. FIRE-80X, Elwood G. Lewis, Philadelphia;- Pa. 2 Application Obtbber 31, 1940; sedative scam? (01'. its-1).

2; Claims.

In connection with the installation off oil burners in domestic orindustrial-'- heating systems; and more" especially" in connection with conversion jobs,'that is;- instances in whichan ordinary coal burning furnaceis to be converted to receivean oil burner; it is necessary to-build a; refractory lining'in the ash pit and" the lower part ofthe combustion chamber so that the-flame of'theoil burner is effectively surrounded by the refractory"materialand prevented from contacting the metal'walls ofthe furnace proper or the water jacket which sometimes forms a part of the furnace. Such refractory lininghas, until relatively-recently,"beenproduced by building the desired wall or liningfrom individual bricks madeofthe: desired refractory-material and se-' cured togethercwithrefractory cement: in-.- volved' considerable time" and labor and; with-,the ordinary type of bricks; it? was practically impossible to produce thevery desirable: streamlined" contour.

As an" improvement on. this" general: practice it has been suggested to pr'e-cast wall'sections of' predetermined contour by means'of'which a firebox or combustion chamber lining could be built: This type of construction isperhapstbest exemplified" the' Eisentra'ger" Patent No. 2075433;

My invention relatesto' an improvedform of pre-cast fire box.the construction and advantages: of which will be more. clearly understood from the .iollowingspecification and the accompanying drawing in. which:

Fig.1 represents a.v top plan. view ofv a: precastfire box embodying my invention.

Fig. 2- represents afront-v elevation of. Fig. 1-.

Figs. 3. to 7 inclusivei represent perspective views of the. sections from whichmy novel precast fire box is built.

Referring; to" the drawing in which like reference characters indicate like parts, and. more particularly to Figs. 6 and 7, it will be seen that I utilize two identical and symmetrical pre-cast bottom sections A and B each of which consists of the flat bottom surface 8, the vertical, inner abutting edges ill, the front, vertical walls l2 and the outer side walls l4. Each of the bottom sections A and B is dished as at 16 so as to leave a bottom or base of a predetermined thickness and a vertical wall 20 also of a predetermined thickness, it being noted that the vertical wall 20 terminates in the slightly thicker front wall portion 22. From Figs. 1, 6 and 7 it will be seen that the bottom sections A and B and B. as'shown' in Fig. 1".

havea; curvilinear contour of" a generallyoval" or pear shape form-when assembled:

Referring to Fig; 4-, I have shownapersp'ec tive view of the back wall section forming part of my invention and which consists of the and cemented in; position; it also overlaps and serves to: hold together:- the abutting edges: of the bottom: sections A and B1 As-will beseenfrom Figs-- I" and 4; the" back wall section 2.14 is provided with: an overhanging flange or' visor 26"for a purpose hereinafter described;

In Fig". 3 Ijhaveshown an" outside perspective View of one" of' the sidewall sections-(band in Fig; 5' I have shown; an. inside. perspective view of the' similar"? side wallj section D: Referring more specifically to- Figs. .3 and 5, it" will beseen thatz'the side wall" sections 0 and Beach-30cm:- prise 3.;VBII'ICE1, curvilinear"wall28- and a front; angularly disposed'wa'll-tfl, it being noted: that the thickness and curvature or the contour of the side wall sections C and-Di correspondto'the thickness, shape and contour of the portions X-Y, XY of the bottom sections and B: After the sectionsAand; B have been cemented together in: abutting position and" the" rear secticn 24*has also been cemented. in' position, the side wallsC and D1 are" placedover-the bottom sections A and. B withthe rear edges 32' or the side. sections C andD abutting against" the edges 314 of." the; rear section- 24; and with thebottom edges 36' and" 38' of th'e side sections C and D resting" on the;.W8J11S20" and" 22 of" thesections A and B. The sections-C and Dare ofcour'se cemented to the rear section 24 and the bottom sections A and B. It will be noted that the front walls 3!! of the side sections 0 and D are molded with arcuate openings 40 which merge into the straight walls 42 so that, when the parts are all assembled (and as will be seen from the front elevational view of Fig. 2) an arch'ed opening is produced through which the barrel of the oil burner is adapted to be inserted. It will be noted that the straight edges 22 of the sections A and B constitute the floor of the arched opening so that the barrel of the oil burner can be rested on the front edges 22. In this connection it is pointed out that the oil burner is usually set at about seven inches from the floor and I therefore make the vertical height of the walls l2 and 20 of seven inchesor of any desired height at which it is desired to set the burner. After the barrel has been inserted and set as suggested, any clearance between it and the wall of the arched opening is of course plugged up with refractory cement.

As will be clearly seen from Figs. 1, 6 and 7, my pre-cast fire box presents an entirely streamlined, internal contour free from all angles or corners whatever thus preventing the carbonization which results from the deposit of carbon in inaccessible and relatively cooler corners which would be present in a structure formed of bricks or of other pre-cast sectional formations which do not present the same continuous, internal, streamlined contour. that the oval shape provides a relatively large space-at the center and rear of the fire box toward which the flameis directed, and that it provides a relatively restricted front area so that, after the flame islrefiected by the rear wall 24, the heat, as well as the flame itself, are evenly distributed, 7 The overhanging flange 26 serves as a battle or defiector and causes the flame, which hits the rear wall 24, to roll or curve back uponitsel'f in the directionof the narrow, front portion of the fire box. The sections A and B serve .as a streamlined flooring for the fire box so that any uncombusted drippings or fuel which may collect when the burner fails to ignite or when the ignition ceases-before the oil burner pump stops functioning will not be allowed to seep into inaccessible corners where the fuel can carbonize but will, on the contrary, be maintained in the smooth, rounded,v dished portion of the sections A and B so that, when the burner is lighted again and. the heat attains the necessary degree, such drippings will burn completely and leave no soot or carbon. Also, the thickness of the base portions or bottoms of the sections A and B form an insulation between the heat and the floor thus preventing loss of h'eat by conduction and the dished contour [6 serves to reflect the heat upwardly more effectively than would be the case if the bottom of the fire box were flat.

Having thus described my invention, what I claim as new anddesire to secure by Letters Patent is: I l l. fAIpre-cast fire box comprising a base section of a generally forwardly tapering pear shaped formation and having a bottom and a vertical wall, said vertical wall being curvilinear throughout its major portion and having a straight front portion, a back section adapted to rest upon the rear portion of the vertical wall of said base section and comprising a vertical wall of a curvature correspondingto the curvature of said rearportion and an upper forwardly overhanging flange, and a pair of side sections adapted to rest on the remaining opposite portions of said base section, each of said side sections comprising a curved vertical wall conforming to the curvature of the corresponding portion of the vertical wall of said base section and a straight front wall corresponding to the straight portion of said base section, the lower juxtaposed portions of the straight front walls of said side section being cut away whereby an opening is formed at the junction of said straight front walls with each other and with the straight portions of said base section.

2. A pre-cast fire box comprising a dished base section of a generally forwardly tapering pear shaped formation and having a generally concave bottom and a vertical wall, said vertical wall be- It will also be noted mg curvilinear throughout its major portion and having a straight front portion, a back section adapted to rest upon the rear portion of the vertical wall of said base section and comprising a vertical wallof a curvature corresponding to the curvature of said rear portion and an upper forwardly overhanging flange, and a pair of side sections adapted to rest on the remaining opposite portions of said base section, each of said side sections comprising a curved vertical wall conforming to the curvature of the corresponding portion of the vertical wall of said base section and a straight front wall corresponding to the .straight portion of said base section, the lower juxtaposed portions of the straight front walls of said side section being cut away whereby an opening is formed at the junction of said straight front walls with eachother and with the straight portions of said base section.

3. A pre-cast fire box comprising two symmettrical parts which, when assembled in abutting position, produce a generally forwardly tapering pear shaped base section having a dished bottom and a vertical wall, said vertical wall being curvilinear throughout its major portion and having an angularly disposed straight front portion, a back section adapted to straddle the abutting rear-portions of the vertical walls of said base sectionand comprising a correspondingly curved vertical wall and an upper forwardly overhanging flange, and a pair of side sections adapted to rest on the remaining portions of said base section, each of said side sections comprising a vertical wall conforming tovthe curvature of the corresponding portion ofthe. vertical wall of said base section and an angularly disposed straight front wall adapted to rest on the front straight wall of said base section, the lower juxtaposed portions of the straight front walls of said side sections being cut away whereby an opening is formed at the junction of said straight front walls with each other and with the straight portions of said base sections.

' ELWOOD C. LEWIS. 

